The decision to pick up the 30th Anniversary Edition of “The Little Mermaid” really comes down to personal preference. If you already own a copy, the bonus features aren’t likely to entice you and the idea of upgrading may not appeal. However, if you don’t own “The Little Mermaid” yet or the idea of digging into the process of its creation sparks interest, heck, even if the notion of seeing the film presented in greater detail and vividness is enough, then there’s little to be disappointed by in Disney’s eighth addition to their Signature Collection.